Liquid crystal display devices have excellent features such as high definition, low profile, light weight, and low power consumption. In recent years, a market scale of liquid crystal display devices has been rapidly increasing. In liquid crystal display devices, dot inversion driving in which a polarity of signal electric potentials supplied to a data signal line is inverted every 1 horizontal scanning period has been widely employed. However, in the dot inversion driving, polarity inversion frequency of the data signal line becomes high. This results in occurrence of problems such as reduction in pixel charging rate and increase in power consumption. In view of this, Patent Literature 1 for example proposes block inversion driving in which a polarity of signal electric potentials supplied to a data signal line is inverted every plural horizontal scanning periods. This block inversion driving allows an improvement in pixel charging rate and suppression of power consumption and heat generation, as compared with the dot inversion driving.
Patent Literature 1 discloses an arrangement in which a dummy scanning period is inserted immediately after polarity inversion in block inversion driving as shown in FIG. 36. According to the arrangement, a dummy scanning period (third horizontal scanning period in FIG. 36) for pre-charging and a horizontal scanning period (fourth horizontal scanning period in FIG. 36) for main charging (writing) are assigned to data (n+2) that comes immediately after the polarity inversion. This allows an increase in charging rate of a pixel corresponding to the data (n+2).
As a measure for improving viewing angle dependence of gamma characteristics (for example, holding down excess brightness and the like in a screen), Patent Literatures 2 and 3 for example disclose an arrangement in which a plurality of sub-pixels in a pixel are controlled to have different brightness so that a halftone is displayed by an area coverage modulation of these sub-pixels (multi-pixel mode).